1. Field of the Invention
The present invention relates to ice making equipment, and more particularly to highly mechanized and automatically controllable equipment wherein ice cans, each filled with ice block, are selectively lifted and transferred by an overhead travelling crane to a stripping-off area, where each ice block is stripped off from a respective ice can.
Further, the present invention generally improves the process of ice making by providing automatic process control, such as agitation of water fed into the ice cans, to ensure high quality of the ice blocks. The ice blocks formed in accordance with the present invention have uniform density and are entirely transparent, even through to the core portion of each of the ice blocks.
2. Description of the Prior Art
In conventional ice making plants, overhead travelling cranes have been employed, however, the engagement and disengagement of a lifting hook with a pair of lugs on the ice can has been manually made by one or more workers. Further, after the hook of the overhead travelling crane has been engaged with the lugs of the ice can or can unit, additional operations have conventionally been manually performed by one or more workers who move along following the travel of the crane.
The above-described disadvantages and inconveniences are attributable to the fact that the engagement and disengagement of the hook with the lugs of the can or ice can unit, as well as lifting and closing of the lid on the ice cans, had to be manually performed by the workers.
Although conventionally a plurality of ice cans are grouped to form ice can units, there has remained undesirable spaces between the cans where the lugs are provided. Therefore, the pitch of the array of ice cans has become non-uniform at such places, where excessive amounts of freezing brine flows, resulting in non-uniformity between the array of ice cans and naturally giving rise to variations in the quality of the produced ice blocks.
Moreover, some ice blocks formed by the prior art system have inevitably been found to be poor in transparency due to smoky white core portions. Such ice blocks are also non-uniform with respect to both density and hardness and cannot be given a high-grade rating.
According to the prior art method, agitation of the water in each ice can has been performed by blowing air into water to obtain ice blocks of good quality. To this end, branch pipes and sub-branch pipes are carried to a main pipe which is connected to the exhaust port of an air compressor installed in the plant. In order to obtain transparent ice blocks, it has been necessary to carry and connect such branch pipes and sub-branch pipes to the main pipe concurrently with dipping of the ice cans filled with brine into one or more ice making tanks. However, such concurrent steps require a large amount of manpower. Moreover, manual carrying and connecting of the heavy branch pipes is considerably heavy labor for the workers, and minimizing such heavy labor as well as reducing required manpower has long been desired.
The sub-branch pipes must be taken up as the amount of ice in the ice can increases in order to prevent the pipes from being caught and held fixed by the frozen ice blocks, and such work also has conventionally been performed manually by one or more workers. It has also been desired to improve this manual operation from the viewpoint of the worker's health.
Another problem attendant the conventional method is that during the course of formation of ice in each ice can, water called "core water" gathers towards the core portion of the ice can due to the fact that water solidifies into ice from the inner periphery of the ice can toward its center. Any impurities or foreign matter in the water are likely to accumulate in this "core water."
Accordingly, it has also been found necessary to exchange the core water with fresh water in order that wholesome ice blocks are formed, and such exchanging of the core water has also been manually performed, and has been a serious problem in an ice making plant where a large number of ice cans are used and handled.
In order to provide automation and improvement of working conditions in an ice making plant, the problems encountered in exchanging the core water must necessarily be solved.
The present inventors have completed a series of related inventions in view of the various problems encountered in ice making plants and have filed a number of patent applications in Japan.
Such Japanese applications comprise:
Japanese Laid-Open (Unexamined) Utility Model Publication No. 116060/78; and PA1 Japanese Laid-Open (Unexamined) Patent Publication Nos. 53053/78, 40410/78, 36059/78, 36060/78 and 24159/78.
The present invention solves the problems and shortcomings attendant the conventional ice making techniques.